CN101242086B

CN101242086B - Ice and snow fusion method for air power transmission line

Info

Publication number: CN101242086B
Application number: CN2008100098038A
Authority: CN
Inventors: 陈宜中; 傅雅芬
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-02-06
Filing date: 2008-02-06
Publication date: 2010-12-01
Anticipated expiration: 2028-02-06
Also published as: CN101242086A

Abstract

The present invention provides a method for melting the ice on the overhead electric transmission line, under the original load of the three-phase electric transmission line by connecting the major loop of the thyristor between each phase line of the circuit with ice and the earth standing for the zero potential through an electric brake, the phases are respectively obtained from three phase lines, the phase signals are accessed into the respective pulse generator to generate lower-edge positive pulse by each generator, the positive pulse is used for triggering the control pole of thyristor in a same phase line to lead to the earth-conducting of the thyristor in order to increase the heat generating quantity of the conducting wire, the pulse generator is also provided with a pulse triggering time regulator with which the conducting time of the thyristor is controlled to lead to that the heat generating quantity of the electric transmission line confirms to the requirement for melting the ice thereby realizing the purpose that the power is not off when the ice is melted on the overhead electric transmission line.

Description

Ice and snow fusion method for air power transmission line

Technical field

A kind of electric wire ice-melt snow method, especially ice and snow fusion method for air power transmission line.

Background technology

Electric power is defeated by the user from afar, must be on the post tower of overhead insulation with Electric wire support, but to winter when snowing, snowflake descends slowly and lightly and build-ups ice on electric wire, form the ice and snow circuit, and ice and snow is long-pending more thick more, electric wire weight is heightened, accident takes place to cause that the post tower of wire short-circuiting, fracture, stringing is toppled over etc., and the ice and snow circuit as the heavy snow at the beginning of 2008 forms brings about great losses to southern area.Present de-icing method mainly is by artificial deicing, also has a kind of electric power to remove ice machine in Canada, car is reached be subjected to low-tension current to be connected on electric wire two ends below the freezing electric wire, removes ice and snow on the electric wire by the heat energy of electric current.But this vehicle must send very big electric energy, cost is expensive, efficient is low, electric wire accumulated snow for long distance seems powerless, therefore also impracticable, also the someone advocates on high-voltage line to increase the line of the deicing that is used for heating, transmitting electricity by turns, is the heat that produces in the time of can not utilizing original transmission line electricity consumption but do one like this, the 2nd, increase single line.These all are to adopt all the period of time step-down short-circuit method in a word, therefore can not utilize the heat of original load current generation and have only the operation of power failure ability.

Summary of the invention

The objective of the invention is: release a kind of the power failure and elevated line is carried out the method for ice-melt snow.

The object of the present invention is achieved like this: ice and snow fusion method for air power transmission line, it is characterized in that: under the original load of three phase line, through between each root phase line that electric brake is connected on the ice and snow circuit with the anode and the negative electrode main circuit of thyristor and the earth of representing zero potential, form the thyristor major loop, on three phase lines, respectively obtain phase place by three instrument transformers, with this phase place signal access pulse generator separately, make each generator before the π phase angle, produce the lower edge positive pulse, trigger the control utmost point that is connected on thyristor in the same phase line with this positive pulse, make this thyristor earth-continuity to increase the lead caloric value, also have the pulse-triggered time regulator in the pulse generator, by the ON time of adjuster control thyristor, it is required to make the caloric value of transmission line meet ice-melt snow.。

Like this, the one, because circuit itself is under the load condition,, can reach 70 ℃ as lead when the summer so the electric current of circuit itself has made transmission pressure generate heat, in addition higher.Therefore need only the heat that keeps original lead to produce because of electricity consumption in winter, on lead, increase the purpose that one part of current just can reach ice-melt snow again, this method that increases additional heat, utilize thyristor just to realize easily, the line current 600-1200A of general 110kV transmission line, the line current 600-1200A of 220kV transmission line, and the rated operational current of existing thyristor can reach 8000A, withstand voltage reaching more than the 10KV, thyristor operating frequency can reach 1000Hz, and above (each data of silicon carbide thyristor in the research and development can also exceed an order of magnitude than existing product now.) for the output impedance that changes small thyristor with increase withstand voltagely, also can or be connected in parallel on each root phase line and represent between the earth of zero potential the thyristor circuit simply connected of (or a plurality of series connection), make the thyristor running parameter needs that more conform to the actual situation.The 2nd, just moment conducting of thyristor during the sinusoidal wave angle convergence of voltage zero-bit belong to the gap shorting mode, so it can also be transmitted electricity in all the period of time to the user before the π phase angle.Though waveform diminishes, but owing to all insert thyristor on every circuit, and all make it before the π phase angle, produce lower edge ripple positive pulse, three-phase line totally still tends to be balanced like this, just can not cause the accident to general electrical appliance by measures such as capacitance compensations, and the sands are running out that needs snow melt in a year, so just having guaranteed need not have a power failure just makes the whole piece overhead transmission line melt deicing snow.The 3rd, carry out step-down owing to utilize near the phase angle of null value, so do not need ad hoc low-voltage equipment.The 4th, the heat energy that is used for cooling off thyristor still can utilize.

Description of drawings

Fig. 1 is circuit theory explanation of the present invention.

Fig. 2 is a thyristor ON time schematic diagram in an ac cycle.

Embodiment

A among Fig. 1, B, C are three phase lines from power transmission terminal output, and D is the ground connection zero line in the power transmission terminal.Be that example illustrates operation principle of the present invention only now with the C phase line.L on the C phase line is a mutual inductor coil, and K1 is the electric brake of instrument transformer, and MF is a pulse generator, and F1, F2 are pulse amplifying circuits, and VT1, VT2 are two thyristors (as the SCR of 12KV/8000A or the IGCT of 6KV/4000A).K2 is the thyristor electric brake, and RW is the overcurrent fuse.Consider that the overhead power transmission high pressure can reach hundreds thousand of volts, therefore a plurality of thyristor serial connections can be formed, draw the thyristor of two serial connections among this figure, as the situation explanation of when serial connection (when increasing electric current as need, also can be again and link between C phase line and ground wire with the thyristor after a plurality of serial connections.) only need get final product with the SCR of a 12KV/8000A when if high pressure is ten thousand volts, at this moment can remove F2, VT2 among the figure.When running into the snowfall freezing weather, K1, K2 close, at this moment instrument transformer is input to the alternating current phases on the C phase line among the pulse generator MF that has the pulse-triggered time regulator, this pulse generator can adopt the circuits for triggering principle in the thyristor power regulating eqiupment, owing to belong to ordinary skill, be not described further here.The identical Pulse Electric signal in two groups of phase angles from pulse generator output, respectively hang oneself F1, F2 amplifies, and insulation each other, being input to the control of controlled thyristor separately then extremely goes up, ON time to thyristor is carried out identical control, when the electric wave pulse triggers thyristor before the π of Fig. 2 phase angle, and the thyristor conducting, the thyristor conducting is to π point zero phase, and reverse voltage will make thyristor end again.By the pulse-triggered time regulator, regulate the thyristor ON time, just the power transmission line total current can be adjusted to the snow melt optimum state because electric current too senior general cause waste of energy.Because ground wire D is by the set ground wire of front power transmission terminal, the line current that therefore is subjected to thyristor control mainly is this section circuit from the front power transmission terminal to thyristor, and general of the power transformation substation in a city needs to install once this device of cover can realize goal of the invention.

Curve representation AC sine wave among Fig. 2, t are the time axis, and U is the voltage axis, and T represents ac cycle, 0, π, 2 π represent the phase angle, and t1 represents that thyristor is subjected to the time point of triggering and conducting before the π phase angle, dash area is a thyristor ON time section.Because the triggering phase place of coming from instrument transformer is consistent with thyristor major loop phase place, so each ac cycle, in the near zero phase of the half cycle time period, thyristor be conducting once.

Claims

1. ice and snow fusion method for air power transmission line, it is characterized in that: under the original load of three phase line, through between each root phase line that electric brake is connected on the ice and snow circuit with the anode and the negative electrode main circuit of thyristor and the earth of representing zero potential, form the thyristor major loop, on three phase lines, respectively obtain phase place by three instrument transformers, with this phase place signal access pulse generator separately, make each generator before the π phase angle, produce the lower edge positive pulse, trigger the control utmost point that is connected on thyristor in the same phase line with this positive pulse, make this thyristor earth-continuity to increase the lead caloric value, also have the pulse-triggered time regulator in the pulse generator, by the ON time of adjuster control thyristor, it is required to make the caloric value of transmission line meet ice-melt snow.